<template>
  <div>
    <!-- 面包屑导航 -->
    <el-breadcrumb separator-class="el-icon-arrow-right">
      <el-breadcrumb-item :to="{ path: '/home' }">首页</el-breadcrumb-item>
      <el-breadcrumb-item>商品管理</el-breadcrumb-item>
      <el-breadcrumb-item>添加商品</el-breadcrumb-item>
    </el-breadcrumb>

    <!-- 卡片视图区域 -->
    <el-card>
      <!-- 信息提示区域 -->
      <el-alert title="添加商品信息"
                type="info"
                center
                show-icon
                :closable="false">
      </el-alert>

      <!-- 步骤条区域 -->
      <el-steps :space="200"
                :active="activeIndex - 0"
                finish-status="success"
                :align-center="true">
        <el-step title="基本信息"></el-step>
        <el-step title="商品参数"></el-step>
        <el-step title="商品属性"></el-step>
        <el-step title="商品图片"></el-step>
        <el-step title="商品内容"></el-step>
        <el-step title="完成"></el-step>
      </el-steps>

      <!-- tab栏区域 -->
      <el-form :model="addForm"
               :rules="addFormRules"
               ref="addFormRef"
               label-width="100px"
               label-position="top">
        <el-tabs v-model="activeIndex"
                 :tab-position="'left'"
                 :before-leave="beforeTabLeave"
                 @tab-click="tabClicked">
          <el-tab-pane label="基本信息"
                       name="0">
            <el-form-item label="商品名称"
                          prop="goods_name">
              <el-input v-model="addForm.goods_name"></el-input>
            </el-form-item>
            <el-form-item label="商品价格"
                          prop="goods_price">
              <el-input v-model="addForm.goods_price"
                        type="number"></el-input>
            </el-form-item>
            <el-form-item label="商品重量"
                          prop="goods_weight">
              <el-input v-model="addForm.goods_weight"
                        type="number"></el-input>
            </el-form-item>
            <el-form-item label="商品数量"
                          prop="goods_number">
              <el-input v-model="addForm.goods_number"
                        type="number"></el-input>
            </el-form-item>
            <el-form-item label="商品分类"
                          prop="goods_cat">
              <el-cascader v-model="addForm.goods_cat"
                           :options="cateList"
                           :props="cateProps"
                           @change="handleChange"></el-cascader>
            </el-form-item>
          </el-tab-pane>
          <el-tab-pane label="商品参数"
                       name="1">
            <!-- 渲染表单item项 -->
            <el-form-item :label="item.attr_name"
                          v-for="item in manyTableData"
                          :key="item.attr_id">
              <!-- 复选框组 -->
              <el-checkbox-group v-model="item.attr_vals">
                <el-checkbox :label="cb"
                             v-for="(cb, i) in item.attr_vals"
                             :key="i"
                             border></el-checkbox>
              </el-checkbox-group>
            </el-form-item>
          </el-tab-pane>
          <el-tab-pane label="商品属性"
                       name="2">角色管理</el-tab-pane>
          <el-tab-pane label="商品图片"
                       name="3">定时任务补偿</el-tab-pane>
          <el-tab-pane label="商品内容"
                       name="4">定时任务补偿</el-tab-pane>
        </el-tabs>
      </el-form>
    </el-card>
  </div>
</template>

<script>
export default {
  data () {
    return {
      //   所有商品分类数据
      cateList: [],

      // 当前激活的步骤条索引
      activeIndex: '0',
      //   添加商品的表单数据对象
      addForm: {
        goods_name: '',
        goods_price: 0,
        goods_weight: 0,
        goods_number: 0,
        // 商品所属的分类数组
        goods_cat: [],
      },

      //   添加商品的表单验证规则对象
      addFormRules: {
        goods_name: [
          { required: true, message: '商品名称不能为空', trigger: 'blur' },
        ],
        goods_price: [
          { required: true, message: '商品价格不能为空', trigger: 'blur' },
        ],
        goods_weight: [
          { required: true, message: '商品重量不能为空', trigger: 'blur' },
        ],
        goods_number: [
          { required: true, message: '商品数量不能为空', trigger: 'blur' },
        ],
        goods_cat: [
          { required: true, message: '商品分类不能为空', trigger: 'blur' },
        ],
      },

      cateProps: {
        label: 'cat_name',
        value: 'cat_id',
        children: 'children',
        expandTrigger: 'hover',
      },

      // 动态参数列表
      manyTableData: [],
    }
  },

  created () {
    this.getCateList()
  },

  methods: {
    //   获取所有商品分类数据
    async getCateList () {
      const { data: res } = await this.$http.get('/categories')
      if (res.meta.status !== 200)
        return this.$message.error('获取商品分类数据失败')

      this.cateList = res.data
    },

    // 级联选择器变化触发的函数
    handleChange () {
      if (this.addForm.goods_cat.length !== 3) {
        this.addForm.goods_cat = []
      }
    },

    // 标签页改变触发的函数
    beforeTabLeave (activeName, oldActiveName) {
      if (oldActiveName === '0' && this.addForm.goods_cat.length !== 3) {
        this.$message.error('请先选择商品分类')
        return false
      }
      return true
    },

    // 标签页被点击触发的事件
    async tabClicked () {
      if (this.activeIndex === '1') {
        const { data: res } = await this.$http.get(
          `categories/${this.cateId}/attributes`,
          { params: { sel: 'many' } }
        )

        if (res.meta.status !== 200)
          return this.$message.error('获取动态参数列表失败')

        res.data.forEach((item) => {
          item.attr_vals =
            item.attr_vals.length === 0 ? [] : item.attr_vals.split(' ')
        })
        this.manyTableData = res.data
      }
    },
  },

  computed: {
    cateId () {
      if (this.addForm.goods_cat.length === 3) {
        return this.addForm.goods_cat[2]
      }
      return null
    },
  },
}
</script>

<style lang="less" scoped>
.el-checkbox {
  margin: 0 15px 0 0 !important;
}
</style>